https://seoft.tistory.com/10

UnitTest에 LiveData사용시 에러.kt

package kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock

import android.content.Context
import androidx.arch.core.executor.testing.InstantTaskExecutorRule
import androidx.lifecycle.LiveData
import androidx.lifecycle.Observer
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.rule.ActivityTestRule
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.data.BookRepo
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.data.api.createGsonFactory
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.data.api.createOkHttpFactory
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.data.api.createWebService
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.data.local.PrefRepo
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.data.model.Book
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.ui.main.MainActivity
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.ui.main.MainVM
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.ui.sub.SubVM
import kr.co.seoft.std_of_android_with_kt_mvvm_aac_mock.util.get
import org.junit.Assert.assertEquals
import org.junit.Before
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith
import java.sql.Timestamp

/**
 * ref :
 * https://www.slideshare.net/imkimkevin/android-jetpack-viewmodel-and-testing
 * https://medium.com/pxhouse/unit-testing-with-mutablelivedata-22b3283a7819
 * https://bonoogi.postype.com/post/3514910
 * https://mvnrepository.com/artifact/androidx.arch.core/core-testing/2.0.0-alpha1
 * https://eclipse-owl.tistory.com/8
 */

@RunWith(AndroidJUnit4::class)
class ViewModelTest {

    val DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"

    @JvmField
    @Rule
    val main = ActivityTestRule(MainActivity::class.java)

    @JvmField
    @Rule
    val instantTaskExecutorRule = InstantTaskExecutorRule()

    lateinit var context: Context
    lateinit var mainVM: MainVM
    lateinit var subVM: SubVM

    var callbackOrder = 0

    fun <T> LiveData<T>.observeByOrder(observer: Observer<T>, _order: Int) {
        if (_order != callbackOrder) return
        observeForever(object : Observer<T> {
            override fun onChanged(t: T?) {
                observer.onChanged(t)
                removeObserver(this)
                callbackOrder++
            }
        })
    }

    @Before
    fun setUp() {
        context = main.activity
        mainVM = MainVM(PrefRepo(context))
        subVM = SubVM(
            BookRepo(
                createWebService(
                    createOkHttpFactory(),
                    createGsonFactory(DATE_FORMAT),
                    BuildConfig.BASE_URL
                ), BuildConfig.AUTH_KEY
            )
        )

    }

    @Test
    fun testMainVM() {

        // clickSearch

        var latelyStr: String? = null

        mainVM.clickSearch("")
        assertEquals(latelyStr, mainVM.doSearch.value)

        val keyword = "테스트"
        mainVM.clickSearch(keyword)
        assertEquals(keyword, mainVM.doSearch.get())

        latelyStr = keyword

        mainVM.clickSearch("")
        assertEquals(latelyStr, mainVM.doSearch.get())


        // calc

        val myBook1 = Book(
            arrayListOf("aut1", "aut2"),
            "this_is_contents",
            Timestamp(System.currentTimeMillis()),
            1000,
            800,
            "this_is_title"
        )

        mainVM.calc(myBook1)
        assertEquals(-800, mainVM.balance.get())

        val myBook2 = Book(
            arrayListOf("aut1", "aut2"),
            "this_is_contents",
            Timestamp(System.currentTimeMillis()),
            1000,
            900,
            "this_is_title"
        )

        mainVM.calc(myBook2)
        assertEquals(100, mainVM.balance.get())

    }


    @Test
    fun testSubVM() {

        val abcTestKeywrod = "abc"
        val androidTestKeyword = "android"
        val rxjavaTestKeyword = "rxjava"

        // check init value
        assertEquals(1, subVM.page)
        assertEquals(1, subVM.refreshCount)


        // search abc
        subVM.addData(abcTestKeywrod)

        subVM.doRefresh.observeByOrder(Observer {
            assertEquals(11, subVM.books.size)
            assertEquals(2, subVM.page)
            subVM.books.forEach {
                if(it is Book) assertEquals(true, it.title.contains(Regex("(?i)abc")))
            }

            // search android
            subVM.addData(androidTestKeyword)
        }, 0)

        subVM.doRefresh.observeByOrder(Observer {
            assertEquals(21, subVM.books.size)
            assertEquals(3, subVM.page)
            subVM.books.forEach {
                if(it is Book) assertEquals(true, it.title.contains(Regex("(?i)android")))
            }

            // search rxjava
            subVM.addData(rxjavaTestKeyword)
        }, 1)

        subVM.doRefresh.observeByOrder(Observer {
            assertEquals(31, subVM.books.size)
            assertEquals(4, subVM.page)
            subVM.books.forEach {
                if(it is Book) assertEquals(true, it.title.contains(Regex("(?i)rxjava")))
            }

            // cleared list
            subVM.clearBooks()

            assertEquals(1, subVM.page)
            assertEquals(1, subVM.refreshCount)
            assertEquals(1, subVM.books.size)

        }, 2)

    }

    @Test
    fun testSubVM2() {

        val emptyResultTestKeyword = "34[@？&*vf2narㄱ㈜tyi2q[ac!@()vs"

        assertEquals(1, subVM.page)
        assertEquals(1, subVM.refreshCount)

        subVM.addData(emptyResultTestKeyword)

        subVM.doEmptyData.observeForever {
            assertEquals(1, subVM.page)
            assertEquals(1, subVM.books.size)
        }
    }


}